[COLDFEAR]

i was out at a friends house last night and she drove out fine. she sat infront of the house for about 2 hours and i came out and tryed to start her and nothing...the check engine light doesnt come on when i turn the key so im guessing that means the PCM isnt starting up. any advice? i have had problems with the positive battery cable connecting to the battery idno if that would affect it. cause i do have power just not to the PCM.

[ZeeJay1997]

I would check battery cables and fuses before calling the PCM bad.

[COLDFEAR]

fuses are all good. and everything else has power....

[ZeeJay1997]

Save yourself some grief and be sure you are getting battery power, fused ignition, and ground to the PCM. Just because everything else is powering up doesn't mean the PCM is getting power.

I don't have a diagram, maybe someone can tell you which pins to check. With the power up check not showing on the cluster when ignition is turned on, one of two things: power is missing or PCM is indeed shot.

[camboman5]

Originally Posted by ZeeJay1997

I don't have a diagram, maybe someone can tell you which pins to check. With the power up check not showing on the cluster when ignition is turned on, one of two things: power is missing or PCM is indeed shot.

If you go to www.jeepslimited.com they have service manuals for most jeeps so you should be able to locate a wiring diagram and everything you need to know about replacing parts for your heep. Be sure you register a username and password, then go to the Download tab at the top (DL tab will only appear if you are a registered member).

Hope that helps.

[draphty]

Been thru this. Check the power and ground input pins at the PCM connector. Also make sure your bulb is good for the CEL on the dash. If you're gettting power and a good ground, and the bulb is good, figure on the PCM. Also, try this, with the ignition on, push your overdrive on/off switch. If the light above the switch does not light up, get yourself a PCM. Hope this helps, if you need pin callouts, go here for a manual posted on-line for a '93 ZJ.

http://www.scribd.com/doc/4790750/93ZJ-Secc-14-Fuel-System

Section 14 Page 70.

Not sure who posted this, but I found it when I was having the same issue. Also search for post's by me on this Forum and on Jeeps Unlimited Forum for more info from others that helped me out. Good Luck!